Messages in this thread | | | Subject | Re: [alsa-devel] [PATCH 4/9] ASoC: tegra: add Tegra210 based I2S driver | From | Sameer Pujar <> | Date | Wed, 22 Jan 2020 12:46:07 +0530 |
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On 1/22/2020 11:53 AM, Dmitry Osipenko wrote: > External email: Use caution opening links or attachments > > > 22.01.2020 07:32, Sameer Pujar пишет: > [snip] >>>>>> +static int tegra210_i2s_remove(struct platform_device *pdev) >>>>>> +{ >>>>>> + pm_runtime_disable(&pdev->dev); >>>>>> + if (!pm_runtime_status_suspended(&pdev->dev)) >>>>>> + tegra210_i2s_runtime_suspend(&pdev->dev); >>>>> This breaks device's RPM refcounting if it was disabled in the active >>>>> state. This code should be removed. At most you could warn about the >>>>> unxpected RPM state here, but it shouldn't be necessary. >>>> I guess this was added for safety and explicit suspend keeps clock >>>> disabled. >>>> Not sure if ref-counting of the device matters when runtime PM is >>>> disabled and device is removed. >>>> I see few drivers using this way. >>> It should matter (if I'm not missing something) because RPM should be in >>> a wrecked state once you'll try to re-load the driver's module. Likely >>> that those few other drivers are wrong. >>> >>> [snip] >> Once the driver is re-loaded and RPM is enabled, I don't think it would use >> the same 'dev' and the corresponding ref count. Doesn't it use the new >> counters? >> If RPM is not working for some reason, most likely it would be the case >> for other >> devices. What best driver can do is probably do a force suspend during >> removal if >> already not done. I would prefer to keep, since multiple drivers still >> have it, >> unless there is a real harm in doing so. > I took a closer look and looks like the counter actually should be > reset. Still I don't think that it's a good practice to make changes > underneath of RPM, it may strike back.
If RPM is broken, it probably would have been caught during device usage. I will remove explicit suspend here if no any concerns from other folks. Thanks. > >>>>>> + int rx_fifo_th; >>>>> Could rx_fifo_th be negative? >>>> rx_fifo_th itself does not take negative values, explicit >>>> typecasting> is avoided in "if" condition by declaring this as "int" >>> Explicit typecasting isn't needed for integers. >> What I meant was, rx_fifo_th is checked against a 'int' variable in an >> "if" condition. > What's the problem with comparing of unsigned with signed?
consider this example, ---- unsigned int x = 5; int y = -1;
(x > y) is false. ---- Hence should be careful while using signed and unsigned comparisons. > > Besides, cif_conf.audio_ch > I2S_RX_FIFO_DEPTH can't be ever true, isn't > it? I2S_RX_FIFO_DEPTH=64, channels_max=16
Yes true. > Lastly, nothing stops you to make max_th unsigned.
will update.
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